South Korea's benchmark gave back its brief trip above 7,000 and closed at 6,625.93 on October 8, even as Samsung Electronics reported a record quarterly operating profit above 100 trillion won, because foreign and institutional investors sold into rising U.S. Treasury yields and the end of heavy chaebol buybacks.

According to Korea Exchange data, the Kospi fell 177.97 points, or 2.62 percent, on the final session of the week. Over three trading days foreigners unloaded a net 6.4692 trillion won while institutions shed 2.3887 trillion won. Retail buyers absorbed 6.2 trillion won but could not offset the block sales.

Earnings versus flows

Samsung's print beat consensus, yet its shares still dropped 2.42 percent on the day. SK hynix fell 2.44 percent. Analysts said the market had already priced memory strength and was now focused on whether profits can hold once support from treasury stock purchases fades.

Samsung completed scheduled open-market buybacks on October 6 after acquiring 106.7 percent of its announced tranche. SK hynix had executed 83.3 percent of its plan as of last week and is expected to finish this month. Kim Seok-hwan, a researcher at Mirae Asset Securities, told local media the question is whether earnings alone can stabilize prices without those corporate bid books.

Macro calendar

Traders enter the week watching U.S. September consumer price data due October 14 in Seoul evening hours. Headline CPI is expected around 3.6 percent year on year, up from 3.4 percent in August. Hotter prints could push the 10-year Treasury yield, which touched 5.36 percent last week, back toward multi-decade highs and widen the valuation gap for Seoul tech names.

Domestic releases include October 1-10 trade figures Monday and bank earnings later in the week. Taiwan Semiconductor Manufacturing Co.'s results on October 15 will offer a second read on AI-related demand after Seoul's memory rally.

Positioning

Strategists at Daishin Securities said a stabilization in oil prices and a softer U.S. inflation read could reopen a path toward 6,800, while a hawkish surprise might test 6,500 support. With buyback support thinning, fund managers said they are trimming leveraged Kospi products that had crowded the market during the holiday-shortened week.

Individual investors remain net buyers for the year, but the latest session showed how quickly that flow can be overwhelmed when global rates move. Until CPI clears, many desks are keeping cash ready for dips rather than chasing reopening gaps.